Acellular Pathogens
Virus that immediately destroys its host cell after replication is following this type of life cycle
What is the lytic cycle?
Structure is formed by complement proteins and creates holes in bacterial cell membranes, causing the cells to burst
What is the membrane attack complex (MAC)?
A small, exposed surface region of an antigen that antibodies and T cells actually recognize and bind to
What is an epitope?
Reaction where a patient develops anemia after receiving blood from an incompatible donor. Antibodies bind to donor RBC antigens, activating complement and destroying the cells
What is Type II Hypersensitivity?
This type of immunity occurs when a person receives ready-made antibodies from another source rather than producing their own immune response
What is passive immunity?
This protein shell surrounds and protects the genetic material of a virus
What is a capsid?
This group of inflammatory molecules contributes to fever and pain by affecting blood vessels and nerve endings
What are prostaglandins?
In this process, natural killer cells recognize and destroy target cells coated in IgG antibodies using their receptors
What is antibody-dependent cell-mediated cytotoxicity?
This type of graft occurs when tissue is transferred between two genetically different individuals of the same species, such as a kidney donated from one human to another
What is an allograft?
These three types of immune cells are the major antigen-presenting cells: dendritic cells, macrophages, and these antibody-producing cell precursors
What are B cells?
Process where a bacteriophage accidentally picks up DNA from one bacterium and carries it to another bacterium
What is transduction?
This innate immune defense does not require antibodies or memory cells but provides immediate protection by physically removing harmful particles from the respiratory tract
What is the mucociliary escalator?
Found primarily on antigen-presenting cells like macrophages and B cells, these molecules present exogenous peptides to CD4+ T helper cells
What are MHC Class II molecules?
Individuals with this blood type have A antigens on their red blood cells and naturally produce antibodies against the B antigen
What is Type A blood?
Unlike immortalized cell lines, these cells more closely resemble the normal cells found in the original tissue but have a limited ability to divide.
What are primary cells?
This technique allows scientists to detect viral genetic material in a patient sample without needing to grow the virus first
What is PCR (polymerase chain reaction)?
These are common molecules found on bacteria, viruses, and fungi that allow the immune system to recognize that a pathogen is present
What are PAMPs (Pathogen-Associated Molecular Patterns)?
Mechanism of peripheral tolerance occurs when a T cell recognizes an antigen without receiving necessary co-stimulatory signals, leading to a state of prolonged unresponsiveness
What is anergy?
In this autoimmune disease, the immune system attacks the myelin sheath surrounding nerve fibers
What is multiple sclerosis?
Type of vaccine that contains weakened virus or bacteria
What is a live attenuated vaccine?
During this early stage of viral infection, the virus attaches to cells, enters the cells, and begins taking over the host cell machinery, but no new viruses are detected yet
What is the eclipse period?
An organized nodular aggregate of differentiated macrophages, formed during a persistent immune response to sequester and contain a pathogen
What is a granuloma (chronic inflammation)?
Induced by cytokines from helper T cells, this genetic mechanism allows a activated B cell to change the constant region of its antibody heavy chain—such as shifting from IgM to IgG—without altering its antigen specificity.
What is antibody class switching?
A close match of these antigens between donor and recipient helps reduce the risk of transplant rejection
What are HLA antigens?
The blood-brain barrier relies heavily on these structures to restrict the movement of many substances into the brain
What are tight junctions?